Diagnosis and classification of chondral knee injuries: comparison between magnetic resonance imaging and arthroscopy

PURPOSE

To compare the magnetic resonance imaging (MRI) findings of patients undergoing knee arthroscopy for chondral lesions. The hypothesis was that MRI displays low sensitivity in the diagnosis and classification of chondral injuries.

METHODS

A total of 83 knees were evaluated. The MRIs were performed using the same machine (GE SIGNA HDX 1.45 T). The MRI results were compared with the arthroscopy findings, and an agreement analysis was performed. Thirty-eight of the 83 MRI exams were evaluated by another radiologist for inter-observer agreement analysis. These analyses were performed using the kappa (κ) coefficient.

RESULTS

The highest incidence of chondral injury was in the patella (14.4 %). The κ coefficient was 0.31 for the patellar surface; 0.38 for the trochlea; 0.46 for the medial femoral condyle; 0.51 for the lateral femoral condyle; and 0.19 for the lateral plateau. After dividing the injuries into two groups (ICRS Grades 0-II and Grades III and IV), the following κ coefficients were obtained as follows: 0.49 (patella); 0.53 (trochlea); 0.46 (medial femoral condyle); 0.43 (medial plateau); 0.67 (lateral femoral condyle); and 0.51 (lateral plateau). The MRI sensitivity was 76.4 % (patella), 88.2 % (trochlea), 69.7 % (medial femoral condyle), 85.7 % (medial plateau), 81.8 % (lateral femoral condyle) and 75 % (lateral plateau). Comparing the radiologists' evaluations, the following κ coefficients were obtained as follows: 0.73 (patella); 0.63 (trochlea); 0.84 (medial femoral condyle); 0.72 (medial plateau); 0.77 (lateral femoral condyle); and 0.91 (lateral plateau).

CONCLUSION

Compared with arthroscopy, MRI displays moderate sensitivity for detecting and classifying chondral knee injuries. It is an important image method, but we must be careful in the assessment of patients with suspected chondral lesions.

LEVEL OF EVIDENCE

III.

First measurement of the transverse spin asymmetries of the deuteron in semi-inclusive deep inelastic scattering

First measurements of the Collins and Sivers asymmetries of charged hadrons produced in deep-inelastic scattering of muons on a transversely polarized 6LiD target are presented. The data were taken in 2002 with the COMPASS spectrometer using the muon beam of the CERN SPS at 160 GeV/c. The Collins asymmetry turns out to be compatible with zero, as does the measured Sivers asymmetry within the present statistical errors.